GD-ROM Dumping Guide

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Revision as of 20:49, 19 March 2023

GD-Rom and GD-R dumping guide.

Note: Some GD-Roms may NOT dump with these method, and require a TOSEC-style SD Card dump for the HD area which then has to be "fixed" to meet redump spec. If the game is a single track in the HD area, then the TOSEC-style dump will be equal a redump dump for HD area, LD area still needs Plextor dumping. See GD-ROM SD Card Dumping Guide.

What are GD Discss?

GDs (Gigadiscs) are the type of optical media used by the Sega Dreamcast as well as the Sega NAOMI, Sega NAOMI 2, Sega Chihiro, and Triforce arcade systems. GD-ROMs are pressed, GD-Rs are recordable discs.

The disc contains two distinct areas, a Low Density (LD) Area and a High Density (HD) Area, physically separated by a ring. To get a good dump, you need to extract both Areas from the disc.

Tools

First you need to make sure you have the necessary equipment. To dump a GD you need:

• Windows PC
• Recommended optical disc drive(s) (see also: Optical Disc Drive Compatibility for GD-ROMs and GD-R Dumping)
• MPF application (includes DiscImageCreator)
• DCDumper, ice, startstop applications
• Audio Trap Disc

Dumping the LD Area

The LD Area should be dumped with using the Disc Dumping Guide (MPF) with a CD-ROM compatible drive.

The LD Area is formatted like a standard CD-ROM.

Dumping the HD Area

Dumping the HD Area can take over an hour sometimes, and your drive may make scary noises. To dump the HD Area of the GD-ROM, a Swap Disc technique is used. There are two ways to do the Swap Disc technique:

• Prepare a Drive for Top Removal as seen in this video tutorial. Afterwards, set the top back onto the drive with screws removed, this allows for easy top removal. Make sure your drive lid is replaced perfectly, putting your drive lid on unevenly can lead to the dump failing partially into the dumping process.
• Pin Eject: Push the tray back into the drive quickly so the spindle will catch.

Method 1: DCDumper (Preferred for GD-ROM Dumping)

A video tutorial for this dumping method can be seen here.

This method is the more reliable method for dumping GD-ROMs because:

• DCDumper dumps disc segments multiple times and compares hashes for QC, it does not rely on /c2 error correction.
• The recommended TSST drives read GD-ROMs best, and do not support /c2 error correction.

Dumping:

• Insert the Audio Trap Disc to an HD Area compatible drive.
• In command line, cd (change directory) to the "DCDumper_ice_startstop" folder.
• Run startstop [DriveLetter] 1
• Remove the top off the drive.
• Insert the GD-ROM and put the drive top back on.
• Run dcdumper [DriveLetter] -c446261 -df -ft -t0 -p20
• It will take several "PASS"es to get all matches, this is fine. If you need to stop (sometimes there is no progress for 30mins) and restart the dumping process, it will continue where it left off - so don't delete progress if you have to stop it.
• When the HD Area dump completes, you'll convert it to it's final form. Run ice.exe dense.bin 44990 > gamename.txt This will produce a bunch of files starting with "Track 03" and going as high as however many tracks were on the HD section of the disc (as little as 1, as many as 98).

If dcdumper fails to run with an error complaining about MSVCP100.DLL being missing, install the Microsoft Visual C++ 2010 Redistributable Package (x86) to fix this issue.

Method 2: DiscImageCreator (Preferred for GD-R Dumping)

This method is more reliable for GD-Rs because:

• GD-Rs do not read on the TSST drives that work so well with GD-ROMs.
• c2 error re-reading is very useful. Since DiscImageCreator can use /c2 error correction, dumping with a compatible Plextor model is preferred.

Dumping:

• Insert the Audio Trap Disc to an HD Area compatible drive
• In command line, cd (change directory) to the folder containing "DiscImageCreator.exe"
• Run DiscImageCreator.exe stop [DriveLetter]
• Remove the top off the drive
• Insert the GD disc and run: DiscImageCreator.exe close [DriveLetter]
• Then run the dumping command: DiscImageCreator.exe gd [DriveLetter] foo.bin [DriveSpeed(0-72)] /c2 (Note #1: " /c2" is only for use with compatible Plextors. Note #2: Adding the command "/be pack" may[1] be helpful when dumping GD-Rs.)
• Dump multiple times until you get an error-free dump (check the Command Prompt output after DiscImageCreator finishes dumping)

Note for GD-R dumping:

• 1x, 4x, 8x read speeds can be helpful or even necessary when dumping GD-Rs. Try starting with 8x, if one of those speeds doesn't work then try another.
• If you have issues where the drive locks up partway through, disabling cache flushes helps: DiscImageCreator.exe gd [DriveLetter] foo.bin 8 /c2 /f 600000

Submitting your dump info

Here's an example submission: [2]

We'll presume you've used Disc Image Creator for you dump in both LD and HD Areas.

Open your "!submissionInfo.txt" file from both your LD and HD Area dump. Copy in the additional track information from your HD Area !submissionInfo.txt file into your LD Area !submissionInfo.txt file in three sections:

• "DAT"
• "Cuesheet". When combining Cuesheet data for LD and HD Areas, paste "REM SINGLE-DENSITY AREA" at the top of the cuesheet, and "REM HIGH-DENSITY AREA" in a new line after the LD Area cuesheet into, then finally the HD Area cuesheet text.
• "Write Offset". For determining write offset for HD Area of a DCDumper + ice.exe dump, open the .txt file output by Ice:
  • Combined offset = Disc offset + Drive offset
  • Kreon drives used for DC dumping have a +6 offset
  • So for Kreon drives, 30 = Disc offset + 6 , resulting in a Disc offset of +24 (for the disc used in this example)
  • If not dumping with a Kreon, the actual drive's offset will need to be input in place of the "+6" for Kreons.

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